Apollo 17 crew, 1972. The first photograph of the fully illuminated Earth from space. Most-reproduced image in history.
From Wikipedia
The Blue Marble is a photograph of Earth taken on December 7, 1972, by one of the astronauts aboard the Apollo 17 spacecraft on its way to the Moon. Viewed from around 29,400 kilometers from Earth's surface, a cropped, rotated, and processed version has become one of the most reproduced images in history.